Touring the Gardens by the Bay attraction in Singapore on Wednesday, Prince William spoke more candidly than ever about his plans to have children with his wife, Duchess Kate, and the ideal size he'd like for his own royal family. "Someone asked him how many children he would like to have, and he said he was thinking about having two," 17-year-old student Corin Ackerman revealed.

(Indeed, now would be a great time to start on baby number one: Earlier this year, a royal insider told Us Weekly that the Duke and Duchess of Cambridge, both 30, hope to conceive a child anytime between the last leg of their royal tour in Asia and summer 2013.)

As the royal couple were greeted in the sweltering heat by 1,000 fans at the Gardens, another teen approached Kate about a similarly urgent topic: Her hair! "I asked her how she kept her hair so perfect in this weather, because it's so humid," Ella Major, 15, said. "Mine always poufs up. She was afraid that her hair might be the same way in a few minutes. She said that her hair would pouf up soon enough!"

William himself even apologized for the heat when shaking the hands of Kate Holt and her daughter Isabel, 14. "Sorry, I'm a bit sweaty," he said.

(The royal couple planted a pachira glabra variegated tree to commemorate their visit to the gardens. "It's amazing," the Duchess said as they left. "I hope we can come back in a few years when it's fully grown.")

Later that day, the couple donned safety goggles to visit a newly opened Rolls-Royce jet engine factory. Kate, looking stunning in a white Alexander McQueen broderie anglaise suit, tested out a new state-of-the art engine -- testing its limits as she put her hand on the throttle. "Did that sound okay?" she asked engineers.